Bahan



J. F. McGARRAHAN.

DOUBLE SEAL SPRING CAP. APPLICATION man DEC. 11. 1920.

Patented May 23, 1922.

UNITED STATES PATENT OFFICE.

JOHN FREDK. MCGARRAHAN. OF CONGRESS PARK. ILLINOIS. J? .SSIGNOR TO 3'. S. GILES & SONS, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

DOUBLE-$1315.14 SPRING CAP.

Specification of Letters Patent. Patgntgd \[ay 23, 1922,,

Application filed December 17, 1920. "Serial n. 431,382.

To all whom it may concern:

Be it known that I, JOHN F. MCGAR- RAHAN, a citizen of the United States, residing at Congress Park, in the county of Cook, State of Illinois, have iuvented certain new and useful Improvements in Dou ble-Seal Spring Caps, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in double seal spring caps for metal containers, and more particularly to spring caps of the screw-threaded type.

An object of the invention is to provide a container and cap of the above character wherein the sealing disk is firmly gripped throughout an extended region so as to produce a very tight joint, thus permitting products'of' more or less of a volatile na ture to be packed and perfectly sealed.

In the drawings which show by way of illustration one embodiment of the invention Figure 1 is a sectional view through the upper part of a container containing my improvement;

Fig. 2 is a similar view, but showing a slightly modified form of flange and channe 3 is a similar View, but also showing a modified shaping of the flange, and Fig. 4 is a view similar to Fig. 1, but showing the cap and sealing disk before being applied to a container.

The invention consists broadly in a container having an inturned flange at its month which may be horizontal or curved in cross section, and the inner edge of'the flange inaylie in the plane of the flange or slightly bent downward. The container. adjacent the mouth thereof is screw-threaded and adapted to receive a screw-threaded cap of the usual construction, so far as the interlocking threads are concerned. In the cap is a sealing disk, preferably made of some suitable packing such as felt, with the lining face of lead or some other soft metal. This disk is of substantially the same diameter as the cap and will be frictionally held within the cap. The cap is formed with a central indented portion or spring panel, and between said indented portion and the depending portion of the cap is an'annular channel which is Slightly greater in width than the flange extending about the opening into the can body. This indented portion is of slightly less diameter than the opening into the can body so that when the cap is screwed on to the can body, the sealing disk will be bent or forced into the opening in the can body and the inner edge portion of the flange will be embedded in the sealing disk and thus a very tight seal formed. 'Furtherrnore, the inner edge of the flange is free and unsupported so that said flange may yield to the force incident to the turning of the cap on to the can body until the shoulder at the outer edge of the flange is likewise embedded in the sealing disk so that there is a tight seal both at the inner and outer edges of the flange on the can body surrounding the opening into the same as well as a tight seal all the way across the flange.

Referring more in detail to the drawings, I have shown in Fig. l a metal container 1 having the mouth or top portion 2 thereof of smaller diameter than the body and this mouth portion is formed with a screw thread. For closing the container I have provided a metal cap 3 which is formed with a depending flange 4 extending down over the top portion'having a screw thread therein adapted to engage with the screw thread on the mouth of the container. These parts are of the usual construction in threaded caps for containers. At the mouth of the container there is an inwardly projecting flange 5 which is horizontal as shown in Fig. 1, while in Fig. 2 I have shown this flange as semicircular or curved in cross section. In Fig. 8, I have shown the flange as horizontal with the extreme inner. edge'6 as bent downward. The cap is provided with a central spring panel or inwardly depressed portion 7. This panel forms a channel 8 all the way around the cap which is directly over the flange 5. The channel as clearly shown in the drawings is slightly greater in width than the flange 5 and extends from the indented portion to the depending portion of the cap. Located within the cap is a sealing disk which preferably consists of a padding 9 having a facing 10 of some soft metal, such as lead. This sealing disk is of substantially the same diameter as the internal diameter of the cap or slightly greater than'the internal diameter so as to be frictionally gripped and held within the cap. When said disk is placed on the cap, it is substantially flat and unbent as shown in Fig. l. When the cap is screwed down on to the container, the sealing disk will be bent or pressed into the opening at the inner edge of the flange and said inner edge of the flange will be embedded in the sealing disk, which, as above noted, is formed of yielding material. The flange is unsupported at it inner edge so that it may yield slightly to the pressure of screwing the top on to the can body. After this inner portion of the flange is embedded in the sealing disk, then the flange yields until the outer edge of the flange is likewise embedded in the sealing disk, and this limits further movement of the cap on to the can body so that the extreme inner edge of the flange forms a sealing line indicated at C in the drawings, as well as a sealing line indicated at A in the drawings, and the seal extends clear across the flange from one line to the other so that a relatively wide seal is formed as well as the two distinct lines of gripping seal caused by the embedding of the flange in the sealing disk. Then again, the channel in the cap has its inner and outer portions more or less rounded and these rounded portions of the channel seek to draw or iron the sealing disk over the flange on the top of the can bodly which further aids in making a tight sea In the form shown in Fig. 2, there is not quite such a sharp bending of the disk, but the curved portion of the flange will more tightly embed the flange within the packing or sealing disk, and thus grip the sealing disk throughout the entire extent of the flange. The same is true of the construction shown in Fig. 3.

The essential features of the invention consist in the proportioning of the flange and the channel so as to bring about this sealing engagement of the flange throughout the entire extent, thus forming a very wlde sealing contact between the container and the disk, and in addition thereto, the sharp gripping orbiting contact between. the inner edge of the flange and the disk, and also more or less of a tight contact at the outer edge of the flange which bites into the disk at a slight distance back of the extreme edge of the disk. This in a sense makes a double seal, plus more or less of a sealing contact from one line of tight sealing to the other line of tight sealmgr As above noted, by my improved form of double seal spring cap, volatile products generating considerable internal pressure may be perfectly sealed within the container. Then again, it often happens that the flange at the mouth of the container becomes indented or bruised during shipping or during filling, and these indentations in the usual form of seal result in leaks, but by my improved extended seal, the flange may be indented at the outer edge and still make a tight seal at the inner edge, or indented at the inner edge and still make a tight seal at the outer edge. These indentations due to handling, seldom extend throughout the entire area and therefore by my improved invention there are seldom leaks caused by indenting of the flange, either during shipment or filling. I

Furthermore, the depressed panel forces the central portion of the sealing disk into the top opening of the container and the springy nature of the panel holds it there, responding more or less to the expansion and contraction caused by the internal pressure. This springy nature of the metal due to the panel construction, aids in the holding of the gasket in sealing contact with the flange.

In the form of the invention shown in Fig. 2, where the flange is curved in cross section; it is obvious that I have provided a reinforce for the flange so that the flange will stand a great deal of pressure during the turning of the cap onto the can without bending the flange so as to not in any way interfere with the sealing quality.

It will be obvious that minor changes in the manner of securing the cap to the container, the details of construction, and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Lettors-Patent, is i 1. The combination with a metal container body having a relatively small topportion provided with an opening into the container body and having an inwardly extending flange surrounding said opening the inner free edge of which is unsupported; of a cap therefor having a'depending portion extending down over the top portion, said cap and top portion having inter-engaging means whereby said cap is securely held on the container body, said cap having a central indented portion of less diameter than the opening into the container and an annular. channel disposed above said flange and extending from said, indented portion to the depending portion of the cap, and a sealing disk of substantially the same diameter as said cap located within and frictionally held in said cap, said indented portion of the cap operating to force the sealing disk into the opening in the container body and thereby embedding the inner edge portion of the flange in said sealing disk and thus forming a tight seal.

2. In combination with a metal container body having a top portion provided withan opening into the containerbody and having an inwardly extending flange surrounding said opening; of a cap therefor, said cap and top portions having inter-engaging means whereby said cap is securely held on the container body, said cap having a central indented portion of less diameter than the opening into the container an annular channel disposed above said flange, and a sealing disk of substantially the same diameter as said cap located Within and frictionally held in said cap, said indented portion of the cap operating to force the sealing disk into the opening in the container body and thereby embedding the inner port-ion of the flange o yield to the pressure of the cap until the 20 shoulder at the outer edge of the flange is embedded in the sealing disk.

In testimony whereof, I aflix my signature. JOHN FREDK. MoGARRAI-IAN. 

